A Work in Progress – Lighting

This weblog post is inspired by Friday’s shopping trip to Jula and Clas Ohlson, two Swedish equivalents of a hardware chain store, in Steinkjer, about 30 km north-east of Cliff Cottage, Vangshylla. On this shopping trip, I ended up buying a number of LED lighting components, not for any specific purpose but for playful learning. There was one impulse purchase, five meters of string lights with sparkly effect!

This is the walkway on the entry level of Cliff Cottage with Trondheim Fjord in the distance. String lighting illuminates the driveway, with 480 LED lights. Two hundred and forty string lights have been temporarily placed along the walkway, to brighten up November, while bags of insulation patiently wait to be fitted into the floor of the attic.

Lighting the stairway

According to my timeline, sometime in 2020, the house will be have a new main stairway. I intend to make it myself, using solid oak. It is difficult to buy hardwood, especially in rural Trøndelag. My solution will be to buy solid oak kitchen counter material which comes 26 (H) x 600 (D) x  2 400 (L) mm ( or about 1″ x 24″ x 96″) , and to cut it into suitable pieces, four treads to a countertop. Materials will cost me about NOK 4 000 (USD 500). Getting someone to make a stairway would cost at least five times that price. Here is a link to what I am thinking about. Biltema can be translated as “car theme”, and is the same in Swedish and Norwegian. It is yet another Swedish chain, even more dominated by male customers, than the two chains previously mentioned.

Before, I start building a new stairway, I want to experiment with lighting. Yes, there will be lighting from above, but I am particularly interesting in lighting each tread, so that old people can distinguish the nosing, and avoid falling. On the two bottom-most treads, I intend to drill holes and fit 4mm (Christmas) lights into them, at about 50 mm intervals. On the next two treads (three and four from the bottom), I intend to fit 100 lm spotlights, one on each side of each tread. If I come across new ideas, I will try them out as well, trying to put the most controversial closest to the bottom.

A Work in Progress

I have no intentions of living in a “finished” house. While the timeline for major improvements stretches over four years from 2018-01-01 to 2021-12-31, the intention is to allow continuous improvement, and to have the house serve as a laboratory in three areas: 1) smart house (computer control using sensors, actuators and communications components), 2) energy reduction with an emphasis on solar thermal energy, 3) assistive technology, including adaptive and rehabilitative devices for the elderly, as well as the general population.

Lighting – The Theory

A lumen (symbol lm) is a measure of the total amount of light visible light emitted by a source in any particular direction.

Lux is a measure of illuminance, how much light there is on a given surface area. One Lux (lx)  equals one lumen per square meter.

ActivityLux
Direct sunlight32 000 – 100 000
Daylight10 000 – 25 000
Full moon1
Kitchen/ workshop ambient100
Kitchen/ workshop task500
Dining/ living area ambient50
Reading/writing400
General task300
Bathroom ambient50
Bathroom task300
Laundry300
Sewing500
Garage/ carport100
Detailed task1 000

Lighting Requirements

Here is a list of lighting requirements in lux for various household activiites. The list has been compiled without recording sources. There is considerable variation in what people need, and standard values will not suit everyone.

Ambient Room Lighting

1. What type of room is it? In this example, it will be assumed that the room is a kitchen.

2. Ambient lighting for a kitchen requires 100 lx.

3. What is the size of the room? For illustrative purposes, assume it is 4 000  x 3 000 mm (4 by 3 meters). This gives an area of 12 square meters.

4. To find the number of lumens, multiply the lux requirement from step 2 by the area from step 3: 100 lx/m² x 12 m² = 1 200 lm.

Clas Ohlson has a 450 mm diameter ceiling light that provides 1 500 lm that would be suitable:

Dot, a dimable 450 mm ceiling light to provide sufficient ambient lighting in a kitchen.

Dot, a dimable 450 mm ceiling light to provide sufficient ambient lighting in a kitchen.
Model36-7503-2
Energy classA
Bulb typeLED
Power24 W
IP classIP54
DimableYes
Lumens1500 lm
Colour temperature2700 K
Colour rendering index (Ra)80
Lighting time1.5 s
Temperature range– 20 to +40 °C
Number of lighting cycles15 000
Lifetime30 000 h
Replacable light sourceNo

Task Lighting

1. Where is the task lighting? In this example, the focus will be on a kitchen counter top – the same one that the stairs were made out of, but this time used more conventionally.

2. Task lighting for a kitchen requires 500 lx.

3. What is the area where the task is taking place? The countertop measures 600 mm x 2 400 mm = 1.44 m², this could be rounded up to 1.5 m².

4. To find the number of lumens, multiply the lux requirement from step 2 by the area from step 3: 500 lx/m² x 1.5 m² = 750 lm.

I had hoped to find something equivalent at Jula, but found this set of downlights at Clas Ohlson: https://www.clasohlson.com/no/LED%20downlights/Pr365874000

As the specifications indicate, 4 downlights would be required to meet the task lighting needs of the countertop work area.

Downlights in a kitchen, but not quite how I would use them.
Model36-5874
Energy classA+
Bulb typeLED
Power3.3 W
IP classIP20
DimableNo
Lumens190 lm
Colour temperature3 000 K
Colour rendering index (Ra)80
Lighting time0.5 s
Temperature range– 20 to +40 °C
Number of lighting cycles100 000
Lifetimeunspecified
Replacable light sourceNo
Diameter: hole/ lamp60/ 65 mm
Depth15 mm
Transformer, able to attach up to six downlights.

One Reply to “A Work in Progress – Lighting”

  1. With respect to string lights along the driveway. The total electrical consumption is 12 W. The system is controlled by a timer, which deactivates the system between 24:00 (midnight) and 07:00. There is also a dusk-to-dawn switch, that cuts out the lighting when sunlight is available. Today, (2018-11-04) sunrise was at 08:06, and sunset will be at 15:51. So the lights are on for a little over an hour in the morning, and a little over 8 hours in the evening. At the winter solstice, they will be off between 10:04 and 14:42, giving us a daytime duration of 4 hours 17 minutes and 29 seconds. After that, life only gets better.

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